Danfoss Drives has entered the $2.5bn medium-voltage drives market with a novel modular design that allows system integrators (SIs) and OEMs to customise their drives and to fit them more easily into tight spaces, such as on board ships. The Vacon 3000 drives will initially cover voltage ratings from 3.3–4.16kV, and power ratings up to 6MW. The range will probably be extended upwards at a later stage.

Although SIs and OEMs account for about half of the business for both LV and MV drives, almost all MV drives are currently delivered from drives-makers as pre-built packages – compared to about 13% for premium LV drives. According to Hans Carlsson, director of pricing strategy and management at Vacon, “this does not make sense”.

He says that that the new modular design will allow SIs and OEMs to integrate MV drives deeper into their systems, to install drives into customer-specific cabinets, to optimise the use of space, and to add more value to projects. “They will not be buying a box pre-designed by the supplier,” he says.

The modules that make up the new system include:

• compact, liquid-cooled inverter modules that can be used in adverse ambient conditions;

• simple, compact pre-charge modules that will limit the inrush current for fast, safe start-ups, and avoid the need for pre-charging resistors;

The modules can be connected in parallel to offer extra flexibility to users.

As well as offering kits of parts, Danfoss has also has produced a reference enclosure design, based on Rittal TS8 enclosures, which SIs and OEMs can use as a template for their own designs. This is available in both IEC and UL versions.

Danfoss is creating a network of Medium Voltage Partners to sell the new drives. “They will have a better control of the design than with standard off-the-shelf products,” says Karl Kyrberg, product manager for the MV drives.

According to Carlsson, the new MV drives will cater for the growing overlap in power ratings and applications between LV and MV drives, with the same site often needing both types of drive. He also points out that, unlike many other MV drives suppliers which bundle their systems with motors, Danfoss supplies only drives and is “unique” is focusing 100% on developing, manufacturing and supplying AC drives.